1. Field of Invention
This invention relates to the field of lawnmowers and, more specifically, to a belt tensioning assembly for use on a rotary mower deck.
2. Description of Related Art
Vehicles such as lawn and garden tractors are often adapted to carry and operate implements such as mower decks which require rotary drive input. To drive the blade or blades of a mower deck, a pulley and belt drive arrangement is commonly provided in which a pulley is coupled with a crankshaft on the vehicle's engine. A V-belt is entrained around the crankshaft pulley as well as a pulley which is operably coupled to the spindles of the mower implement. Problems are commonly associated with conventional drive systems and include slipping or other undesired movement of the belt on the pulleys or the inability to obtain a desired tension in the belt, especially as the mower deck moves relative to the chassis of the mower.
Pulley/belt drive systems are typically tensioned using a back-side idler on the “slack-side” between the last (if more than one) driven pulley and the drive pulley or an inside (typically V-groove) idler. The back-side idler pulley arrangement typically enhances the drive system performance since “belt-wrap” on the drive and driven pulleys is typically increased. However, this arrangement does not function well with drive and driven pulley offsets in the lateral plane exceeding the pulley width or angularities approaching or exceeding 5 degrees since the belt will tend to ride-off the drive or driven pulleys. Inside pulley arrangements typically reduce performance since “belt-wrap” for the drive and driven pulleys is typically decreased.
This invention provides a method and apparatus for providing tension to the belt of a lawn tractor equipped with a mower deck. The difficulties inherent in the related art are overcome in a way that is simple and efficient, while providing better and more advantageous overall results.